Dermatology Online Journal

Acquired Blaschko Dermatitis
Elizabeth K. Hale, M.D.
Dermatology Online Journal 7(1): 8

Department of Dermatology, New York University

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PATIENT: T.B., 64-year-old man

DURATION: Three months

DISTRIBUTION: Left upper extremity, chest, abdomen, back, and buttock

History

The patient presented to the Charles C. Harris Skin and Cancer Pavilion with a one-month history of a non-pruritic eruption that was limited to the left side of his body. There was no history of atopic dermatitis, psoriasis, or any similar previous dermatitis. Past medical history was unremarkable. A biopsy and a potassium hydroxide fungal examination were performed, and topical glucocorticoids were prescribed. The eruption remained unchanged after a six-week course of betamethasone dipropionate ointment.

Physical Examination

Erythematous patches and papules were noted in a reticulate pattern on the left upper extremity and on the left side of the chest, abdomen, back and buttock. The lesions were arranged in whorls and streaks corresponding to Blaschko's lines. The eruption stopped abruptly at the midline of the torso and completely spared the right side of the body.

Figure 1	Figure 2

Laboratory Data

A potassium hydroxide preparation was negative for hyphae.

Histopathology

There is a superficial, perivascular infiltrate of lymphocytes and eosinophils that extends to a hyperplastic epidermis where there are spongiosis and mounds of parakeratosis. A periodic acid-Schiff stain was negative for hyphae.

Diagnosis

Acquired Blaschko dermatitis

Comment

Acquired Blaschko dermatitis, also known as Blaschkite de l'adulte and acquired relapsing self-healing Blaschko dermatitis, was first described in 1990 by Grosshans and Marot in Bordeaux, France.[1] This rare condition is characterized by acquired, unilateral, inflammatory linear lesions that occur along Blaschko's lines and that have a tendency to relapse over time.

The lines of Blaschko were first described in 1901 and represent a pattern that is observed in many skin disorders.[2,3] In contrast to dermatomes, Blaschko's lines form a V-shape over the spine and an S-shape on the lateral and anterior aspects of the trunk. These lines, which are invisible under normal conditions, indicate the normal embryonic movements of the skin that occur during embryogenesis. It has been suggested that the distribution of diseases which occur along Blaschko's lines may be due to a form of mosaicism.[3]

Approximately five cases of acquired Blaschko dermatitis have been reported.[4,5] Neither the etiology nor the pathogenesis of this condition is completely understood. Several of the previously described cases failed to respond to treatment with topical glucocorticoids but responded to systemic glucocorticoid therapy. The condition seems to relapse, especially at times of stress.

References

1. Grosshans E, Marot L. [Blaschkitis in adults] Ann Dermatol Venereol 1990;117(1):9-15. PubMed

2. Jackson R. The lines of Blaschko: a review and reconsideration: Observations of the cause of certain unusual linear conditions of the skin. Br J Dermatol 1976;95(4):349-60. PubMed

3. Bolognia JL, Orlow SJ, Glick SA. Lines of Blaschko. J Am Acad Dermatol 1994;31(2 Pt 1):157-90; quiz 190-2. PubMed

4. Megahed M, Reinauer S, Scharffetter-Kochanek K, Milde P, Holzle E, Goerz G, Ruzicka T. Acquired relapsing self-healing Blaschko dermatitis. J Am Acad Dermatol 1994;31(5 Pt 2):849-52. PubMed

5. Lee HJ, Kang WH, Hann SK. Acquired Blaschko dermatitis: acquired relapsing self-healing Blaschko dermatitis. J Dermatol 1996;23(9):639-42. PubMed

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